Hello @MacSvensson, this reads like https://github.com/ValveSoftware/SteamOS/issues/2504. Can you check if your system is similar?
Thanks! I hadn't found the SteamOS issue during my search, but it does indeed look very similar.
My system currently has no physical capture device available.
During my investigation I tested this hypothesis by creating a dummy capture source in PipeWire:
pactl load-module module-null-source source_name=dummy_mic source_properties=device.description=Dummy-Microphone
The dummy source was created successfully, appeared in PipeWire, and was enumerated correctly by Wine.
However, it did not change the behaviour. The startup delay remained essentially identical. I then unloaded the dummy source again, restarted Steam, and repeated the timing measurements. The results were unchanged.
The only workaround I found that consistently removes the startup delay is:
WINEDLLOVERRIDES="winepulse.drv=d;winealsa.drv=b" WINEALSAOUTPUT=default %command%
Is the SteamOS issue expected to be resolved by the presence of any capture source, or does it specifically require a physical capture device?
proton 9.0x1 2026-08WINEDLLOVERRIDES="winepulse.drv=d;winealsa.drv=b"x1 2026-08WINEDLLOVERRIDES="winepulse.drv=b;winealsa.drv=n"x1 2026-08WINEDLLOVERRIDES="winepulse.drv=d;winealsa.drv=b" WINEALSAOUTPUT=default %command%x1 2026-08WINEDLLOVERRIDES="winepulse.drv=b;winealsa.drv=n" %command%x1 2026-08
Summary
Since a recent system update, every Proton game experiences an approximately 30-second delay between launching the game executable and the appearance of the game window. Replacing winepulse.drv with winealsa.drv removes the delay completely, suggesting a regression in the PulseAudio/PipeWire backend.
System
Games tested
Measured startup times
Age of Wonders III
Launcher: ~8–10 s (same with and without workaround)
Play → fullscreen
Without workaround: 34 / 31 / 31 s
With workaround: 1 / 1 / 1 s
Baldur's Gate 3 (--skip-launcher)
Steam Play → first fullscreen window
Without workaround: 46 / 46 / 47 s
With workaround: 18 / 17 / 17 s
Workaround
WINEDLLOVERRIDES="winepulse.drv=b;winealsa.drv=n" %command%
Additional observations
Expected behaviour
Games should launch without the additional ~30 second delay while using winepulse.drv.
Actual behaviour
Games consistently spend approximately 30 additional seconds during startup when using winepulse.drv.
Question
Is this a known regression in winepulse.drv (or its interaction with recent PipeWire/PulseAudio changes), or is additional debugging information required?
steam-226840.log